Title name of the book is "Kimya-e-Saadat" Alchemy of Eternal Bliss actually in Persian language and written by Imam Ghazali r.a
Imam Ghazali (rahmatullahi alaihi) has a distinguished place in the Islamic history. He was first-rate genius who popularized moral knowledge among the Muslims. According to some well known thinkers and historians of modern world. Ghazali's greatest achievement consisted in dethroning philosophy from the highest pedestal of knowledge and enthroning spiritualism in its place.